Jalpa Design Flaws and Design Weaknesses

The following is a list of design flaws and weaknesses of Lamborghini Jalpa. The list is compiled based on my 1985Jalpaownership experience since 1994 and many attempts of repairs and improvements. Whenever I was not satisfied with a repair, I continued to search for alternatives and only reluctantly went to alternative parts and designs (except for the Electromotive TEC-3 engine management system, fuel injection and twin switchable turbo charging, which gave me additional flexibility and power, see here: for more detail).

The modifications were done at about 53k kilometers, the car still feels fresh, powerful and young.

The list is compiled based on my best engineering judgment and is also to some extent a function of the location of the car, which has always been in southern California.

Laust Pedersen, May-2008

# / Design Flaw / Effect of flaw / Correction(s) / Comments
1 / Engine mounting brackets are too weak / Cracks in engine mounting brackets and for some owners the engine has moved enough to make gearshifts difficult. / New brackets from Raymond Stauffer ( mounted with 4.5 mm thick large stainless washers (98125A443) / These brackets are almost the same as the original in dimension (3% thicker) and material (both appear to be ductile steel). I consider the large thick washers to be a necessity in order not to repeat the past failures.
2 / Door catch are too weak and disintegrate over time / Door will open too wide and bend the sheet metal at the leading edge / Can with some effort and ingenuity be repaired or replaced with part from other car manufacturer(s) / The door catch (with spacer) is a pain to get out and install and required very good manual dexterity.
3 / Catalytic converters (US model) will over time have melted internals / Serious exhaust restriction, resulting in reduced power and engine running hotter under load / New catalytic converters or re-core old ones if authentic look is important. A more expensive solution is converting to better controlled fuel injection. / The Weber carburetors are set to run rich and the OEM cats are of second generation, meaning that the density of the noble metals in the cats is higher than later versions, which makes them more prone to local heating (melting).
4 / Body flex, both in bending and torsional mode. / The car does not feel as “solid” as most other cars. The body flex becomes an integral part of the suspension. / The installation of the Targa Top makes the body somewhat stiffer. / The tunnel cover plates (2mm steel) underneath the car with 34 + 8 mounting bolts serves to stiffen the body, so it is important that it is in place and bolts properly tightened. It may be worthwhile to look into other stiffening braces.
5 / Tachometer is very inaccurate / Could lead to over-revving the engine and setting the idle too low / Characterize the inaccuracies and mentally compensate for the misreading. Check that the rpm limiter functions as intended. / The tachometer reads too high at idle and (maybe 6%) too low at high rpm.
If this is deemed very important then a more accurate aftermarket tachometer can be used.
5 / Tachometer and speedometer have plastic needles which bends toward the glass over time / In extreme cases they can interfere with the glass rendering the instrument almost useless / I had Palo Alto Speedometer (PAS) correct this at a cost of about $500 / PAS upgraded my instruments with aluminum needles.
# / Design Flaw / Effect of flaw / Correction(s) / Comments
6 / Suspension springs sag over time / Too low ground clearance and potential for bottoming out. Will interfere with fender at ~30 deg steering angel / 1)Design and install spacers
2)Re-do entire McPherson set up
7 / Almost impossible access to front sparkplugs on US spec cars before 1986 / Very difficult (impossible?) sparkplug service / Convert to Euro air boxes or have a service opening made. / In 1986 and later models Jalpa got a sparkplug service opening (with lid) into the cabin.
# / Design weakness / Effect of weakness / Correction(s) / Comments
1 / Suspension has no apparent camber adjustment / No problem if car is accident free and well-aligned from the factory / Introducing adjustability beyond camber plates, requires (expensive) engineering. / I have had no problem with this.
2 / Clutch slave cylinder has a limited life (20 years?) / Loss of clutch function / Install a new seal / Seal ($35) available from GTCP. All my components looked good except the original seal had lost tension.
3 / The wheels have identical dimensions F/R and looks a little “tugged in”. There is space for maybe 12” width on the rear. / Cosmetics and maybe slight loss in performance due to higher rear road contact pressure. / Acquire and install Silhouette or early Countach phone dial wheels & tires or have rims widened. / Rims can be widened by any amount inward for $200 each necessitating spacers. This was the route I took.
Jalpa uses BMW bolt pattern, so after-marked BMW wheels with spacers can be used too.